CVE-2014-6271: GNU Bourne-Again Shell (Bash) Arbitrary Code Execution Vulnerability

Is it exploited?

Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 28 Jan 2022, 2,683 days after the CVE record was published.

How likely is exploitation in the next 30 days?

100%

EPSS score, percentile 100 of all scored records

How severe?

9.8 Critical

CVSS v3.1 base score, from CISA's enrichment of the record

What should I do?

CISA deadline 28 Jul 2022. Apply updates per vendor instructions.

Advisories and patches (12)

Which versions are affected?

Not stated. The CVE record gives vendor and product as “n/a” and the version as “unspecified”.

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

What to do

CISA due date for this action: 28 July 2022.

Advisories and patches

• SUSE-SU-2014:1223 (Vendor advisory)
• HPSBMU03165 (Vendor advisory)
• SSRT101816 (Vendor advisory)
• HPSBHF03119 (Vendor advisory)
• RHSA-2014:1295 (Vendor advisory)
• openSUSE-SU-2014:1226 (Vendor advisory)
• HPSBST03131 (Vendor advisory)
• SSRT101819 (Vendor advisory)
• HPSBMU03245 (Vendor advisory)
• openSUSE-SU-2014:1254 (Vendor advisory)
• HPSBMU03143 (Vendor advisory)
• HPSBMU03182 (Vendor advisory)

Linked from CISA's catalog entry

• https://nvd.nist.gov/vuln/detail/CVE-2014-6271

Affected products and versions

The CVE record does not name affected products or versions: vendor and product are “n/a” and the version is “unspecified”.

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

About this vulnerability

GNU Bash through 4.3 processes trailing strings after function definitions in the values of environment variables, which allows remote attackers to execute code.

Summary: CISA's KEV catalog, as of 28 Oct 2026.

• CISA added CVE-2014-6271 to its Known Exploited Vulnerabilities (KEV) catalog on 28 Jan 2022.
• It is widely known as Shellshock, a common name that is not used in the CVE record or in CISA's catalog.
• CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
• The due date CISA sets for the required action is 28 Jul 2022.
• The CVE record was published on 24 Sep 2014, 2,683 days before it was added to KEV.
• The CVE record carries a CVSS v3.1 base score of 9.8 (Critical), taken from CISA's enrichment of the record.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 100% (percentile 100), as of 28 Oct 2026.
• CISA's SSVC assessment in the CVE record: exploitation active, automatable yes, technical impact total.

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.

Description

GNU Bash through 4.3 processes trailing strings after function definitions in the values of environment variables, which allows remote attackers to execute arbitrary code via a crafted environment, as demonstrated by vectors involving the ForceCommand feature in OpenSSH sshd, the mod_cgi and mod_cgid modules in the Apache HTTP Server, scripts executed by unspecified DHCP clients, and other situations in which setting the environment occurs across a privilege boundary from Bash execution, aka "ShellShock." NOTE: the original fix for this issue was incorrect; CVE-2014-7169 has been assigned to cover the vulnerability that is still present after the incorrect fix.

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

Weakness

• CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.

Timeline

References

158 more in the CVE record.

More exploited GNU vulnerabilities

• CVE-2026-24061: GNU InetUtils Argument Injection Vulnerability (added 26 Jan 2026)
• CVE-2014-6278: GNU Bash OS Command Injection Vulnerability (added 2 Oct 2025)
• CVE-2023-4911: GNU C Library Buffer Overflow Vulnerability (added 21 Nov 2023)
• CVE-2014-7169: GNU Bourne-Again Shell (Bash) Arbitrary Code Execution Vulnerability (added 28 Jan 2022)